The references cited in the present application are not admitted to be prior art to the claimed invention.
Neuropeptides present in the hypothalamus play a major role in mediating the control of body weight. (Flier, et al., 1998. Cell, 92, 437–440.) Melanin-concentrating hormone (MCH) is a cyclic 19-amino acid neuropeptide synthesized as part of a larger pre-prohormone precursor in the hypothalamus which also encodes neuropeptides NEI and NGE. (Nahon, et al., 1990. Mol. Endocrinol. 4, 632–637.) MCH was first identified in salmon pituitary, and in fish MCH affects melanin aggregation thus affecting skin pigmentation. In trout and in eels MCH has also been shown to be involved in stress induced or CRF-stimulated ACTH release. (Kawauchi, et al., 1983. Nature 305, 321–323.)
In humans two genes encoding MCH have been identified that are expressed in the brain. (Breton, et al., 1993. Mol. Brain Res. 18, 297–310.) In mammals MCH has been localized primarily to neuronal cell bodies of the hypothalamus which are implicated in the control of food intake, including perikarya of the lateral hypothalamus and zona inertia. (Knigge, et al., 1996. Peptides 17, 1063–1073.)
Pharmacological and genetic evidence suggest that the primary mode of MCH action is to promote feeding (orexigenic). MCH mRNA is up regulated in fasted mice and rats and in the ob/ob mouse. (Qu, et al., 1996. Nature 380, 243–247.) Injection of MCH centrally (ICV) stimulates food intake and MCH antagonizes the hypophagic effects seen with α melanocyte stimulating hormone (αMSH). (Qu, et al., 1996. Nature 380, 243–247.) MCH deficient mice are lean, hypophagic and have increased metabolic rate. (Shimada, et al., 1998. Nature 396, 670–673.) Transgenic mice overexpressing MCH are hyperphagic and develop insulin resistance and mild obesity. (Ludwig, et al., 2001. J. Clin. Invest. 107, 379–386.)
MCH action is not limited to modulation of food intake as effects on the hypothalamic-pituitary-axis have been reported. (Nahon, 1994. Critical Rev. in Neurobiol. 8, 221–262.) MCH can modulate stress-induced release of ACTH. (Nahon, 1994. Critical Rev. in Neurobiol. 8, 221–262.)
Several references describe a receptor that is indicated to bind MCH (“MCH-1R”). (Chambers, et al., 1999. Nature 400, 261–265, Saito, et al., 1999. Nature 400, 265–269, Bächner, et al., 1999. FEBS Letters 457:522–524, Shimomura, et al., 1999. Biochemical and Biophysical Research Communications 261, 622–626.)